#pragma ident "$Id$"

#ifndef GPSTK_MJD_HPP
#define GPSTK_MJD_HPP

//============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 2.1 of the License, or
//  any later version.
//
//  The GPSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//
//  Copyright 2004, The University of Texas at Austin
//
//============================================================================

//============================================================================
//
//This software developed by Applied Research Laboratories at the University of
//Texas at Austin, under contract to an agency or agencies within the U.S.
//Department of Defense. The U.S. Government retains all rights to use,
//duplicate, distribute, disclose, or release this software.
//
//Pursuant to DoD Directive 523024
//
// DISTRIBUTION STATEMENT A: This software has been approved for public
//                           release, distribution is unlimited.
//
//=============================================================================

#include "TimeTag.hpp"
#include "TimeSystem.hpp"

namespace gpstk
{
/**
 * This class encapsulates the "Modified Julian Date" time representation.
 */
class MJD : public TimeTag
{
public:
    /**
     * @defgroup mjdbo MJD Basic Operations
     * Default and Copy Constructors, Assignment Operator and Destructor.
     */
    //@{
    /**
     * Default Constructor.
     * All elements are initialized to zero.
     */
    MJD( long double m = 0.,
         TimeSystem ts = TimeSystem::Unknown )
        : mjd( m )
    {
        timeSystem = ts;
    }

    /**
     * Copy Constructor.
     * @param right a reference to the MJD object to copy
     */
    MJD( const MJD& right )
        : mjd( right.mjd )
    {
        timeSystem = right.timeSystem;
    }

    /**
     * Alternate Copy Constructor.
     * Takes a const TimeTag reference and copies its contents via
     * conversion to CommonTime.
     * @param right a const reference to the BasicTime object to copy
     * @throw InvalidRequest on over-/under-flow
     */
    MJD( const TimeTag& right )
    {
        convertFromCommonTime( right.convertToCommonTime() );
    }

    /**
     * Alternate Copy Constructor.
     * Takes a const CommonTime reference and copies its contents via
     * the convertFromCommonTime method.
     * @param right a const reference to the CommonTime object to copy
     * @throw InvalidRequest on over-/under-flow
     */
    MJD( const CommonTime& right )
    {
        convertFromCommonTime( right );
    }

    /**
     * Assignment Operator.
     * @param right a const reference to the MJD to copy
     * @return a reference to this MJD
     */
    MJD& operator=( const MJD& right );

    /// Virtual Destructor.
    virtual ~MJD()
    {}
    //@}

    // The following functions are required by TimeTag.
    virtual CommonTime convertToCommonTime() const;

    virtual void convertFromCommonTime( const CommonTime& ct );

    /// This function formats this time to a string.  The exceptions
    /// thrown would only be due to problems parsing the fmt string.
    virtual std::string printf( const std::string& fmt ) const;

    /// This function works similarly to printf.  Instead of filling
    /// the format with data, it fills with error messages.
    virtual std::string printError( const std::string& fmt ) const;

    /**
     * Set this object using the information provided in \a info.
     * @param info the IdToValue object to which this object shall be set.
     * @return true if this object was successfully set using the
     *  data in \a info, false if not.
     */
    virtual bool setFromInfo( const IdToValue& info );

    /// Return a string containing the characters that this class
    /// understands when printing times.
    virtual std::string getPrintChars() const
    {
        return "QP";
    }

    /// Return a string containing the default format to use in printing.
    virtual std::string getDefaultFormat() const
    {
        return "%.9Q %P";
    }

    virtual bool isValid() const;

    virtual void reset();

    /**
     * @defgroup mjdco MJD Comparison Operators
     * All comparison operators have a parameter "right" which corresponds
     *  to the MJD object to the right of the symbol.
     * All comparison operators are const and return true on success
     *  and false on failure.
     */
    //@{
    bool operator==( const MJD& right ) const;
    bool operator!=( const MJD& right ) const;
    bool operator<( const MJD& right ) const;
    bool operator>( const MJD& right ) const;
    bool operator<=( const MJD& right ) const;
    bool operator>=( const MJD& right ) const;
    //@}

    long double mjd;
};

} // namespace

#endif // GPSTK_MJD_HPP
